'Super bug' that's resistant to antibiotics threatens hospital patients
Tuesday, August 24, 2010
As intravenous antibiotics dripped into his arm, David Carmody seemed to be recovering nicely from a bad bladder infection. But then out of the blue things got worse as he lay in bed at a rehabilitation center: He felt weaker and began suffering uncontrollable diarrhea.
A battery of tests revealed an entirely new, and serious, problem: Clostridium difficile (or C. diff), a virulent form of bacteria that doctors worry has become a new "super bug" -- increasingly common in hospitals and with growing resistance to antibiotics and virulence among those afflicted.
"I hadn't heard of C. diff. But there it was, eating its way through me," said Carmody, a 55-year-old government retiree from Anne Arundel County, whose multiple sclerosis requires him to use a wheelchair. He recovered after more than a week of heavy-duty antibiotics that still work against C. diff, but "it scared me," he said.
The C. diff strain sickens about 3 million Americans a year, usually attacking people who, like Carmody, have been on antibiotics or in hospitals or other health-care facilities. It can cause severe diarrhea and inflammation of the colon. It is deadly in up to one in 40 cases, particularly when it strikes the elderly and infirm, and contributes to 15,000 to 30,000 deaths annually, according to the Centers for Disease Control and Prevention.
Research shows that the C. diff bacterium rivals the better-known MRSA, or methicillin-resistant Staphylococcus aureus, as a source of hospital-acquired infection resistant to various drugs. A recent study found 25 percent more C. diff than MRSA in 28 community hospitals in Virginia, North Carolina, South Carolina and Georgia.
Becky Miller, an infectious-disease physician at Duke University Medical Center who presented that research at a recent conference, says she believes those statistics reflect what's happening at hospitals across the country and not just in those states.
The findings bolster research published in 2008 in the American Journal of Infection Control showing that C. diff rates had skyrocketed to 13 per 1,000 hospitalized patients, up to 20 times higher than previous estimates. Other studies show MRSA rates on the decline, partly because hospitals have worked to reduce them. (A study published this month in the Journal of the American Medical Association showed a 28 percent decrease in all hospital-onset, invasive MRSA infections over the four-year period from 2005 through 2008.)
"In many areas, C. diff is the number one hospital-acquired infection," said Kevin Kavanagh, a Kentucky physician who runs a patient advocacy organization called Health Watch USA.
A major reason for the surge in cases, doctors said, is the overuse and inappropriate use of antibiotics; Miller pointed particularly to the prescription of more broad-spectrum antibiotics that work against C. diff, including Cipro, for problems such as urinary tract infections that could be treated with drugs designed for a narrower spectrum of bacteria. He said another driver is the increased use of alcohol-based hand sanitizers, which don't kill C. diff spores, instead of soap and water, which does. Hospital officials across the nation say they are working on these issues as they beef up infection control by paying attention to keeping their facilities clean, isolating patients affected by C. diff and ensuring that doctors and nurses wash their hands.
But Kavanagh argues that more must be done, and he says public reporting of C. diff rates would speed things along.
In the meantime, the problem continues to escalate. Carmody, who used to work for the Office of Naval Intelligence, said he contracted C. diff after being treated in a hospital and then a rehab center for a MRSA bladder infection; he developed the infection after a catheter to drain his urine was replaced. He surmises that antibiotics used to treat the first infection helped bring on the second because the medication killed off other bacteria in his body but didn't work against C. diff, allowing it to grow. These days he asks more questions when doctors prescribe antibiotics and makes sure health-care workers wash their hands with soap and water before touching him. "You've got to be vigilant," he said.
A growing danger
The C. diff strain was discovered in 1935 and first associated with disease in 1978. But it has grown more dangerous in recent years, with the CDC in 2004 reporting a new, more virulent strain with the ability to produce greater quantities of certain toxins. Recent studies have also cited cases in which C. diff bacteria were resistant to Flagyl, a common antibiotic.